Semiconductor device and method of manufacturing semiconductor device

ABSTRACT

A method of manufacturing a semiconductor device includes the steps of: mounting a semiconductor chip on a holding board having electrode accommodation recesses formed thereon, and mounting electrode members to the electrode accommodation recesses, the electrode members being formed separately from the semiconductor element; electrically connecting electrode pads formed on the semiconductor chip with the electrode members; forming a resin package for sealing the semiconductor chip on the holding board by using a die, the holding board serving as a part of the die; and separating the resin package including the electrode members from the holding board. A semiconductor device includes: a semiconductor chip; a resin package for sealing the semiconductor chip; electrode members which are embedded in and held by the resin package and which are partly exposed from a mounting surface so as to form external connection terminals; and connecting parts electrically connecting electrode pads on the semiconductor chip with the electrode members.

This application is a Division of prior application Ser. No. 08/962,395filed Oct. 31, 1997, now U.S. Pat. No. 5,891,758.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a semiconductor device and amethod for manufacturing a semiconductor device, and particularlyrelates to a semiconductor device of the leadless surface mounted typeand a resin sealed type and a method for manufacturing suchsemiconductor device.

The pitch of the leads which are provided to a semiconductor of theresin sealed type needs to be ever smaller to achieve furtherminiaturization of electronic devices. Therefore, for the semiconductordevice of the resin sealed type, new structures and manufacturingmethods are required.

2. Description of the Related Art

FIGS. 1A-1C and FIG. 2 show cross-sectioral diagrams of conventionalresin sealed semiconductor devices.

In FIGS. 1A-1C, a semiconductor device includes a resin 1, asemiconductor chip 2, outer leads 3, bonding wires 4 and a die pad 5.This semiconductor device is of a package structure referred to asSSOP(Shrink Small Outline Package) wherein the outer leads 3 bent in agull-wing shape are mounted to a carrying board.

In FIG. 2, a semiconductor device includes the resin 1, thesemiconductor chip 2, the bonding wires 4, solder balls 6 and a carryingboard 7 for mounting the semiconductor chip 2. This semiconductor deviceis of a package structure referred to as BGA(Ball Grid Array) whereinterminal parts to be mounted to a carrying board are formed of thesolder balls 6.

In the SSOP-type semiconductor device shown in FIG. 1, the area of aconnecting part 9 ranging from the inner leads 8 to the outer leads 3,shown in resin 1, and/or the area occupied by the outer leads 3 islarge, so that a problem arises in that the device occupies a large areawhen it is mounted on a board. Also, in the BGA-type semiconductordevice shown in FIG. 2, the manufacturing cost increases due to the useof the carrying board 7.

A semiconductor device which could overcome the above-mentioned problemsis described in Japanese Patent Application No.7-322803. FIG. 3 shows asemiconductor device 110 disclosed in the above application. As shown inFIG. 3, the semiconductor device 110 has a very simple structureincluding a semiconductor chip 111, a resin package 112 and metal layers113. The semiconductor device 110 is characterized in that resinprotrusions 117 formed as part of the mounting surface 116 of the resinpackage 112 are coated with the metal layers 113.

In the semiconductor device 110 constructed as described above, no innerlead or outer lead, as used in a conventional SSOP, is necessary.Therefore, the connecting area from inner leads to outer leads and thearea occupied by the outer leads become unnecessary, so that thesemiconductor device 110 is miniaturized. Also, the manufacturing costof the semiconductor device 110 is reduced since there is no need forusing the carrying board to form solder balls, as were necessary inconventional BGA. In addition, the resin protrusions 117 and the metallayers 113 together provide a function equivalent to that of solderbumps(protruded electrode) of the semiconductor device of the BGA type.This makes it easier to mount the semiconductor device.

As described above, the semiconductor device 110 can bring about variousadvantageous effects which were not obtained by semiconductor devices ofthe prior art shown in FIG. 1 and in FIG. 2.

However, the semiconductor device 110 has a structure in which the metallayers 113 are simply disposed to cover the resin protrusions 117. Atjunction parts between the metal layers and the resin protrusions 117,it is difficult to maintain a sufficient joining force. There wereproblems such that for example during the semiconductor manufacturingprocess or when mounting, the metal layers 113 peel off from the resinprotrusions 117 and reliability of the semiconductor device 110 maydecrease.

Accordingly, there is a need for a semiconductor device and a method ofmanufacturing a semiconductor device which overcomes the above problems.Also, there is a need for a semiconductor device in which reliability isimproved by firmly joining the metal layers and the resin protrusionsand a method of manufacturing such semiconductor device.

SUMMARY OF THE INVENTION

Accordingly, it is a general object of the present invention to providea semiconductor device and a method of manufacturing a semiconductordevice which can satisfy the needs described above.

It is another object of the present invention to provide a method ofmanufacturing a semiconductor device which can surely separate theelectrode members from the holding board when separating the resinpackage from the holding board in a separating process, and can preventthe electrode members from remaining in the holding board. Also, theelectrode members are embedded in the resin package so that theelectrode members are firmly held to the resin package. Because of this,the electrode members will not separate from the resin package and thereliability of the semiconductor device is improved.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the steps or:

a) mounting asemiconductor chip on aholding board having electrodeaccommodation recesses formed thereon, and mounting electrode members tothe electrode accommodation recesses, the electrode members being formedseparately from the semiconductor element;

b) electrically connecting electrode pads formed on the semiconductorchip with the electrode members;

c) forming a resin package for sealing the semiconductor chip on theholding board by using a dee, the holding board serving as a part of thedie; and

d) separating the resin package including the electrode members from theholding board.

In the method described above, the electrode members are formedseparately from the semiconductor element and the electrode members aremounted to the electrode accommodation recesses in step a). Therefore,the joining force between the electrode members and the electrodeaccommodation recesses is smaller compared to the joining force of theconventional structure(see FIG. 21) wherein the metal layers 113 arejoined to the resin protrusion 117 by plating.

It is still another object according to the present invention to providea method of manufacturing a semiconductor device which can reduce thenumber of components and the number of manufacturing steps by notutilizing an adhesion agent, while the semiconductor chip and theelectrode members are easily held to the holding board.

In order to achieve the above object according to the present invention,a method of manufacuring a semiconductor device includes the step a)which further includes the steps of:

forming an element accommodation recess together with the electrodeaccommodation recesses on the holding board for carrying thesemiconductor chip; and

mounting the semiconductor chip on the element accommodation recess sothat the holding board holds the semiconductor chip.

In the method described above, said semiconductor chip is mounted onsaid element accommodation recess so that said semiconductor chip holdssaid holding board. Therefore, the number of components and the numberof manufacturing steps are reduce by not utilizing an adhesion agent.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can securely hold thesemiconductor chip to the holding board by holding the semiconductorchip 11 on the holding board using a tape member which functions as anadhesive member in the step a).

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the step a)further including the steps of:

providing an adhesion member having adhesiveness to the holding board ata position where the semiconductor chip is to be mounted; and

holding said semiconductor chip on said holding board by said adhesionmember.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can surely prevent thesemiconductor chip and the mounting board from being short-circuited andto prevent the semiconductor chip from separating from the resinpackage, thereby improving the reliability of the semiconductor device.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes an area of theadhesive member which is smaller than an area of the semiconductor chip.

In the method described above, by providing the adhesive member in thestep a), a semiconductor chip can be mounted on the holding board apartfrom the surface of the holding board with a distance of the thicknessof the adhesive member. Also, the area of the tape member is smallerthan the area of the semiconductor chip. Therefore a space can be formedbetween the base of the semiconductor chip and the surface of theholding board.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can reduce the risk ofimpurities entering between the semiconductor chip and the electrodemembers and the holding board. This can decrease contamination, andreliability of the semiconductor device is improved. Also, a boundarysurface between the foreign matter and the semiconductor element and theelectrode members can be reduced, so that peeling and/or cracking due tothermal stress at the boundary surface can be reduced. This can alsoimprove reliability of the semiconductor device.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes a step offorming suction holes in the holding board so that both of the step b)and the step c) are performed while the semiconductor chip and theelectrode members are held to the holding board by suction force.

In the method described above, holding can be achieved without usingextra material for holding the semiconductor chip and the electrodemembers (such as holders, herein referred to as foreign matter), byperforming the step b) and the step c) with the semiconductor chip andthe electrode members are held by vacuum to the holding board, therebyachieving the above object.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can form plating layerseasily without damaging the resin package, compared to a method whereina plating process is performed after forming the resin package.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device performs a platingprocess for at least partly forming plating layers on the electrodemembers, before performing the step a).

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can surely separate theelectrode members from the holding board even in the case when thesealing resin enters between the electrode members and the electrodeaccommodation recesses.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the platinglayers formed in said plating process which are made of gold.

In the method described above, the gold layers have less adhesiveness tothe resin sealing, there by achieving the above object.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can perform the step a) ofthe semiconductor device quite easily by using solder as the platinglayers, so that the semiconductor device can be soldered to the mountingboard.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes forming theplating layers in the plating process of solder.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can easily and surelyseparate the resin package from the holding board, even in the case whenthe resin package is formed on the holding board in the step c), sincethe joining force between the holding board and the resin package isweak.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device further includes a stepof applying, before performing the step a), a demolding agent to aportion of said holding board where said holding board comes in contactwith the resin package for weakening adhesiveness against the resin ofsaid resin package and includes gold plating applied to a portion ofsaid holding board where said holding board comes in contact with theresin package.

In the method described above, the demolding agent for weakeningadhesiveness with the sealing resin or the gold layer is provided to thepart of the holding board which contacts the resin package. Thereforethe joining force between the holding board and the resin package isweak.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device in which a space is formed betweenthe base of the semiconductor chip and a mounting board when thesemiconductor device is mounted on the mounting board, so that thesemiconductor chip and the mounting board are prevent from beingshort-circuited.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device which includes theholding board is such that a depth of the electrode accommodationrecesses is larger than a depth of the element accommodation recess.

In the method described above, the electrode members will have a largerdegree of protrusion with respect to the mounting surface(the base) ofthe resin than that of the semiconductor chip, thereby achieving theabove object.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device, which can form the electrodemembers having larger thickness, more easily within a short period oftime as compared to the conventional structure wherein the metal layersare formed by plating.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes an electrodemember forming process which is performed before performing the step a),and in which the electrode members are formed by cutting out a metalplate.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can be treated in a similarmanner to the way the BGA(Ball Grid Array) is treated, so that it iseasier to mount and a multi-pin structure is achieved.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the electrodemembers used in the step a, including one of solder balls and goldballs.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can achieve a fine-pitchstructure and a multi-pin structure by enabling multi-stage bonding, sothat neighboring wires are prevented from touching each other.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the electrodemembers having different heights which are mounted in the step a), sothat connecting performed in the step b) can be performed at differentheights.

It is yet another object of the present invention to provide a method ofmanufacturing a semiconductor device which can prevent the sealing resinfrom entering between the electrode members and the electrodeaccommodation recesses, thereby surely separate the electrode membersfrom the holding plate in the separating process.

In order to achieve the above object according to the present invention,a method of manufacturing a semiconductor device includes the electrodemembers and the electrode accommodation recesses which are stucktogether when the electrode members are mounted on the electrodeaccommodation recesses in the step a).

It is yet another object of the present invention to provide asemiconductor device which can prevent the electrode members fromseparating from the resin package while mounting the semiconductordevice on a mounting board, thereby improving the reliability of thesemiconductor device.

In order to achieve the above object according to the present invention,a semiconductor device includes:

a semiconductor chip;

a resin package for sealing the semiconductor chip;

electrode members which are embedded in and held by the resin packageand which are partly exposed from a mounting surface so as to formexternal connection terminals; and

connecting parts electrically connecting electrode pads on thesemiconductor chip with the electrode members.

It is yet another object of the present invention to provide asemiconductor device which can surely prevent the semiconductor chip andthe mounting board from being short-circuited and to prevent thesemiconductor chip from separating from the resin package, therebyimproving the reliability of the semiconductor device.

In order to achieve the above object according to the present invention,a semiconductor device further includes a spacer on a lower surface ofthe semiconductor chip, the spacer having an area smaller than an areaof the semiconductor device, and a sealing resin forming the resinpackage surrounds the spacer.

It is yet another object of the present invention to provide asemiconductor device which can carry out an operational test for thesemiconductor device after the semiconductor device is mounted on themounting board by touching the extended part with a probe.

In order to achieve the above object according to the present invention,a semiconductor device includes the electrode members which are extendedoutside an outer edge of the resin package.

It is yet another object of the present invention to provide asemiconductor device which can enable multi-stage bonding and can narrowthe pitch between respective electrode members, so that thesemiconductor device can be of multi-pin structure.

In order to achieve the above object according to the present invention,a semiconductor device includes the electrode members which includehigh-back electrode members and low-back electrode members having aheight lower than a height of the high-back electrode members.

It is yet another object of the present invention to provide asemiconductor device which can be treated in a similar manner to the waythe BGA(Ball Grid Array) is treated, so that it is easier to mount and amulti-pin structure is achieved.

In order to achieve the above object according to the present invention,a semiconductor device includes the electrode members which are formedof metal balls.

Other objects and further feature of the present invention will beapparent from the following detailed description when read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C are schematic diagrams showing an example of a semiconductordevice of the prior art.

FIG. 2 is a schematic diagram showing an example of a semiconductordevice of the prior art.

FIG. 3 is a schematic diagram showing an example of a semiconductordevice of the prior art.

FIG. 4 is a cross sectional diagram of a first embodiment of asemiconductor device of the present invention.

FIG. 5 is a schematic diagram showing a mounting process of amanufacturing method of a first embodiment of a semiconductor device ofthe present invention.

FIG. 6 is another schematic diagram showing a mounting process of amanufacturing method of a first embodiment of a semiconductor device ofthe present invention.

FIG. 7 a schematic diagram showing a connecting process of amanufacturing method of a first embodiment of a semiconductor device ofthe present invention.

FIG. 8 a schematic diagram showing a sealing process of a manufacturingmethod of a first embodiment of a semiconductor device of the presentinvention.

FIG. 9 a schematic diagram showing a separating process of amanufacturing method of a first embodiment of a semiconductor device ofthe present invention.

FIG. 10 is a schematic diagram showing a variant of the connectingprocess.

FIG. 11 is a schematic diagram showing a variant of the sealing process.

FIG. 12 is a cross sectional diagram of a second embodiment of asemiconductor device of the present invention.

FIG. 13 is a schematic diagram showing a mounting process of amanufacturing method of a second embodiment of a semiconductor device ofthe present invention.

FIG. 14 is another schematic diagram showing a mounting process of amanufacturing method of a second embodiment of a semiconductor device ofthe present invention.

FIG. 15 a schematic diagram showing a separating process of amanufacturing method of a second embodiment of a semiconductor device ofthe present invention.

FIG. 16 is a cross sectional diagram of a third embodiment of asemiconductor device of the present invention.

FIG. 17 is a schematic diagram showing a completion state of a sealingprocess of a manufacturing method of a third embodiment of asemiconductor device of the present invention.

FIG. 18 is a schematic diagram showing a lead frame which can be appliedin a manufacturing method of a third embodiment of a semiconductordevice of the present invention.

FIG. 19 is a cross sectional diagram of a fourth embodiment of asemiconductor device of the present invention.

FIG. 20 is a schematic diagram showing a connecting process of amanufacturing method of a fourth embodiment of a semiconductor device ofthe present invention.

FIGS. 21A-D are diagrams showing variant embodiments of electrodemembers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, a principle and embodiments of the present inventionwill be described with reference to the accompanying drawings.

FIG. 4 is a cross sectional diagram of a semiconductor device 10 whichis a first embodiment of a semiconductor device of the presentinvention. In general, the semiconductor device 10 includes asemiconductor chip 11, aresin package 12 and electrode members 13A.Therefore the structure of this semiconductor device is quite simple.

A plurality of electrode pads 14 are formed on the upper surface of thesemiconductor device 11. The resin package 12 is formed, for example, bymolding (or potting) epoxy resin as will be later described.

The electrode members 13A, which are cut out of a lead frame materialsuch as copper alloy, serve as external connection terminals. Theseelectrode members 13A are partly embedded in the resin package 12. Thus,the electrode members 13A are firmly held to the resin package in thisembedded structure, so that they will not easily separate from the resinpackage 12. Therefore the electrode members 13A will not separate fromthe resin package 12 while mounting the semiconductor device 10 on amounting board. This improves the reliability of the semiconductordevice.

Wires 18 are provided between the electrode members 13 and theabove-mentioned electrode pads 14, thus making the electrode members 13and the semiconductor device 10 electrically connected. In the presentembodiment, wire-bonding is used as parts connecting the electrodemembers 13 with the electrode pads 14. However, connection of theelectrode members 13 with the electrode pads 14 is not limited towire-bonding and, for example, TAB(Tape Automated Bonding) or flip-chipbonding can also be employed. When using flip-chip bonding, bumps can beprovided either on the electrode members 13A or on the electrode pads 14of the semiconductor chip 11.

In the present embodiment, plating layers 15 are formed on the electrodemembers 13. These plating layers 15 may be made either of gold or ofsolder. If gold is used as the plating layers 15, the electrode members13 are surely protected while electric connection with the mountingsurface is improved. If solder is used as the plating layers 15, thesemiconductor device 10 can be soldered to the mounting board(not shown)by means of the plating layers 15. Therefore, the mounting process ofthe semiconductor device 10 can be performed quite easily.

The plating layers 15 need not be formed on the entire electrode members13, but may be formed at least on the parts exposed from the resinpackage 12. Also, the structure of the plating layers 15 is not limitedto a single-layer structure, but can also be a multi-layer structure soas to correspond to the mounting configuration of the semiconductordevice 10.

In the semiconductor device 10 having the structure as described above,inner-leads and outer-leads of the conventional SSOP are no longernecessary, and the area for connecting inner leads with outer leads orthe area of an outer leads also becomes unnecessary, therebyminiaturizing the semiconductor device 10.

The mounting board, which was necessary in the conventional BGA, forforming solder balls is not required. Because of this, manufacturingcost of the semiconductor device 10 is reduced. Also, it is easier tomount the electrode members 13A since the electrode members 13A areequivalent to bumps(protruded electrodes) of a BGA-type semiconductordevice.

In the semiconductor device 10 according to the above embodiment, theelectrode members 13A were formed by cutting out part of the lead-framematerial. However, metal balls can be used as the electrode members 13A.These metal balls can either be gold balls or solder balls. In asemiconductor device using these metal balls as the electrode members13A, the electrode members 13A are spherical. Therefore thissemiconductor device can be treated in a similar manner to the way theBGA(Ball Grid Array) is treated, so that it is easier to mount and amulti-pin structure is achieved.

The manufacturing method of the semiconductor device according to theabove first embodiment will be described with reference to FIGS. 5-9. Ingeneral, the manufacturing method of the semiconductor device accordingto the present invention includes mounting process, connecting process,sealing process and separating process. Each process will be describedin detail.

First, the mounting process will be described with reference to FIG. 5and FIG. 6. In the mounting process, a holding board 19A havingelectrode accommodation recesses 20A formed thereon is used so as tomount a semiconductor chip 11 on the holding board 19A and to mountelectrode members 13A to the electrode accommodation recesses 20A.

The holding board 19A is formed of metal which has coefficient ofthermal expansion is close to that of the semiconductor chip 11 and theelectrode member 13A. As shown in FIG. 5, a plurality of the electrodeaccommodation recesses 20A is formed such that they surround an elementaccommodation recess 21. The depth of the electrode accommodationrecesses 20A is deeper than the depth of the element accommodationrecess 21. Also, the plane configuration of the element accommodationrecess 21 is constructed so as to match the base configuration of thesemiconductor chip 11, while the plane configuration of the electrodeaccommodation recesses 20A is constructed so as to match the baseconfiguration of the electrode members 13A.

Either cutting work (machining) or etching can be employed as a methodof forming the element accommodation recess 21 and the electrodeaccommodation recesses 20A on the holding board 19A.

In the sealing process described in the following, the resin package 12is formed on the upper surface of this holding board 19A. On thepredetermined part where the resin package is formed on the holdingboard 19A, a demolding agent (not shown) having low joining ability witha sealing resin 25 (the resin package 12) is spread, or a gold layer isformed. Also, at least on the inner surface of the electrodeaccommodation recesses 20A, gold plating is deposited.

As shown in FIG. 6, the semiconductor chip 11 and the electrode member13A are mounted on the holding board 19A having the above structure.This mounting process merely mounts the semiconductor chip 11 on theelement accommodation recess 21 and also mounts the electrode members13A to the electrode accommodation recesses 20A.

During this process, no adhesive agent is spread on the elementaccommodation recess 21 and on the electrode accommodation recesses 20A.The semiconductor chip 11 and the electrode member 13A are held to theholding board 19A simply by the fitting of the semiconductor chip 11 andthe element accommodation recess 21 and by the fitting of the electrodemembers 13A and the electrode accommodation recesses 20A. Therefore thenumber of components and the number of manufacturing steps is reduced bynot utilizing an adhesion agent, while the semiconductor chip 11 and theelectrode members 13A are easily held to the holding board 19A.

The semiconductor chip 11 and the electrode members 13A are formed inadvance by another process. The electrode members 13A are formed by anelectrode member forming process and plating process which are performedprior to the mounting process.

In the electrode member forming process, a lead-frame plate, which maybe made of copper alloy, is subjected to pressing/punching work so as tocut out individual electrode member 13A. The electrode members 13A arethus formed by cutting out the lead-frame plate the in the electrodemember forming process. The electrode members 13A are formed more easilyand more efficiently compared to the conventional structure wherein themetal layers 113 are formed by plating.

Changing the height of the electrode members 13A does not affect theefficiency in forming the electrodes since the height of the electrodemembers 13A is defined by the thickness of the lead-frame plate. Platingthe electrodes can be performed after a sealing process, which isdescribed below, is completed.

However, when the plating process is performed after the completion ofthe sealing process, a formed resin package 12 may be damaged by platingliquid. Therefore, to form plating layers 15 without damaging the resinpackage 12, the plating process is performed before the mounting processand the plating layers 15 are at least partly formed on the electrodemembers 13A in advance.

The electrode members 13A, which have been cut out as described above,are subsequently subjected to a plating process. In the plating process,the plating layers 15 (see FIG. 4) are at least partly formed on theelectrode members 13A. The plating layers 15 can be made of gold or ofsolder. The effect of using gold and the effect of using solder as theplating layers 15 has been previously described, and further descriptionwill be omitted.

After completion of the mounting process, the connecting process isperformed. This connecting process will be describe with reference toFIG. 7. In the connecting process, the electrode pads 14 which areformed on the semiconductor chip 11 and the electrode members 13A areelectrically connected.

In the present embodiment, the wires 18 are used for electricallyconnecting the electrode pads 14 with the electrode members 13A, andwire-bonding is employed as a means for providing these wires 18. Asdescribed above, means for connecting the electrode pads 14 with theelectrode members 13A is not limited to wire-bonding, but TAB(TapeAutomated Bonding) or flip-chip bonding may also be used. Particularlywhen flip-chip bonding is used, the bumps may either be provided on theelectrode members 13A or on the electrode pads 14 of the semiconductorchip 11.

After completion of the connecting process, the sealing process isperformed. This sealing process will be describe with reference to FIG.8. In the sealing process, the holding board 19A is used as a part of amold, and the resin package 12, which seals the semiconductor chip 11 onthe holding board 19A, is formed.

The resin package 12 is formed by mounting the holding board 19A, whichis provided with the semiconductor element 11, the electrode members 13Aand the wires 18, in the mold 22A. This mold 22A consists of anupper-mold 23 and a lower-mold 24, and the holding board 19A is heldbetween the upper-mold 23 and the lower-mold 24.

In the upper-mold 23, a cavity 26 which matches the resin package 12 isformed as well as a gate 33 through which the sealing resin 25 whichwill be the resin package 12 is filled. On the contrary, the lower-mold24 has a flat upper surface since the lower-mold 24 mounts the holdingboard 19A which functions as a part of the mold. Therefore the structureof the lower-mold 24 is simplified, thereby reducing the cost of themold 22A.

As described above, after the holding board 19A is mounted in the mold22A, the sealing resin 25(shown as dotted area) is filled into thecavity 26 through the gate 33. In the present embodiment, molding isused as an example for forming the resin package 12, but potting mayalso be used. FIG. 8 shows a structure wherein the resin package 12 isformed for a single semiconductor chip 11. However, it may be of aso-called multi-cavity structure, where a plurality of the semiconductorchips 11 and the electrode members 13 may be formed on the holding board19A and at the same time a plurality if the cavities 26 may be formed onthe mold 22A.

After completion of the sealing process, the separating process isperformed. This separating process will be describe with reference toFIG. 9. In the separating process, the resin package 12 separates fromthe holding board 19A together with the electrode members 13A.

In the present embodiment, a method is described wherein the resinpackage 12 separates from the holding board 19A together with theelectrode members 13A by pulling out (in the direction of an array) theresin package 12 from the holding board 19A. If the joining forcebetween the holding board 19A and the resin package 12 is large and/orthe joining force between the electrode accommodation recesses 20A andthe electrode members 13A is large, the resin package 12 may crackduring separation, or the electrode members 13A may remain on theholding board 19A.

However, as described above, the joining force between the electrodeaccommodation recesses 20A and the electrode members 13A iscomparatively small, since the structure is such that the electrodeaccommodation recesses 20A and the electrode members 13A are simplyfitted together. Also, the joining force between the electrode members13A and the resin package 12 is large, since the electrode members 13Aare embedded in the resin package.

In the sealing process, when the sealing resin 25 enters between theelectrode members 13A and the electrode accommodation recesses 20A, thissealing resin 25 is equivalent to the adhesive agent for joining theelectrode members 13A and the electrode accommodation recesses 20A. Inthis case, the electrode members 13A may not separate from the electrodeaccommodation recesses 20A. However, in the present embodiment, theplating layers 15 (see FIG. 4), whose adhesiveness with the resin islower than that of gold, are formed on the surface of the electrodemembers 13A and the gold layers are formed on the inside of theelectrode accommodation recesses 20A.

Because of this, when separating the resin package 12 from the holdingboard 19A in the separating process, the electrode members 13A surelyseparate from the holding board 19A and the electrode members 13A areprevented from remaining in the holding board 19A.

In the present embodiment, before performing the mounting process asdescribed above, the demolding agent for weakening adhesiveness with thesealing resin 25 (resin package 12) or the gold layer is provided to thepart of the holding board 19A which contacts the resin package 12.Therefore the joining force between the holding board 19A and the resinpackage 12 is weak. Because of this, the resin package 12 surelyseparates from the holding board 19A without damaging the resin package12 during the separating process.

The semiconductor device 10 shown in FIG. 4 is manufactured byperforming a series of processes described above. In the manufacturingmethod according to the present embodiment, a lead-cutting process and alead-forming process for forming the leads into a predeterminedshape(for example gull-wing shape) are not required. This simplifies themanufacturing of the semiconductor device 10.

Also in the present embodiment, the holding board 19A is used, which hasa structure such that the depth of the electrode accommodation recesses20A is deeper than the depth of the element accommodation recess 21.Therefore in the manufactured semiconductor device 10, the electrodemembers 13A will have a larger degree of protrusion with respect to themounting surface 16 of the resin 12 than that of the semiconductor chip11. Accordingly, a space(indicated by an arrow L in FIG. 4) is formedbetween the base of the semiconductor chip 11 and a mounting board(notshown) when the semiconductor device 10 is mounted on the mountingboard. Because of this, the semiconductor chip 11 and the mounting boardare surely prevented from being short-circuited.

A variant according to the first embodiment of the method ofmanufacturing the semiconductor device will be described with referenceto FIG. 10 and FIG. 11. FIG. 10 shows a connecting process according tothe variant, and FIG. 11 shows a sealing process according to thevariant.

In the variant, it is characterized in that electrode suction holes 27and element suction holes 28 are formed in a holding board 19B. Theelectrode suction holes 27 are formed so as to match the electrodeaccommodation recesses 20A with their top ends opened at the base of theelectrode accommodation recesses 20A and their bottom ends opened at thelower surface of the holding board 19B. The element suction holes 28 areformed so as to match the element accommodation recess 21 with its topend opened at the base of the element accommodation recess 21 and itsbottom end opened at the lower surface of the holding board 19B.

In the connecting process according to the present variant, the holdingboard 19B is mounted on a heater block 30 as shown in FIG. 10. Theheater block 30 heats the electrode members 13A via the holding board19B, so that wire-bonding using a capillary 32 will be performed in agood condition. Also, since ultra-sound bonding is employed in thepresent embodiment, the holding board 19B is fixed to the heater block30 by clamps 29.

The heater block 30 is provided with a suction tube 31 whichcommunicates with the electrode suction holes 27 and the element suctionholes 28. This suction tube 31 is connected to a suction device(notshown) which can be for example a vacuum pump. Therefore, when vacuum iscreated in the suction tube 31 by operating the suction device, thesemiconductor element 11 is held by vacuum to the base of the elementaccommodation recess 21 and the electrode members 13A are held by vacuumto the base of the electrode accommodation recesses 20A. According tothe present variant, the connecting process can be performed with thesemiconductor chip 11 and the electrode members 13A held by vacuum tothe holding board 19B.

An shown in FIG. 11, In the sealing process according to the presentvariant, a lower-mold 24A which forms a part of a mold 22B is providedwith a suction tube 33 which communicates with the electrode suctionholes 27 and the element suction holes 28 formed on the holding board19B. This suction tube 33 is connected to a suction device(not shown)which can be for example a vacuum pump. Therefore, when vacuum iscreated in the suction tube 33 by operating the suction device, thesemiconductor element 11 is held by vacuum to the base of the elementaccommodation recess 21 and the electrode members 13A are held by vacuumto the base of the electrode accommodation recesses 20A. According tothe present variant, the sealing process can be performed with thesemiconductor chip 11 and the electrode members 13A held by vacuum tothe holding board 19B.

Thus, by performing the connecting process and the sealing process withthe semiconductor chip 11 and the electrode members 13A held by vacuumto the holding board 19B, holding can be achieved without using extramaterial for holding the semiconductor chip 11 and the electrode members13A(such as holders, herein referred to as foreign matter).

Because of this, the risk of impurities entering between thesemiconductor chip 11 and the electrode members 13A and the holdingboard 19B is reduced. This decreases contamination, and reliability ofthe semiconductor device is improved. Also, a boundary surface betweenthe foreign matter and the semiconductor element 11 and the electrodemembers 13A is reduced, so that peeling and/or cracking due to thermalstress at the boundary surface can be reduced. This also improvesreliability of the semiconductor device.

In the following, a semiconductor device 10B of the second embodiment ofthe present invention and a method of manufacturing semiconductor device10B is described.

FIG. 12 shows the semiconductor device 10B of the second embodiment.FIGS. 13-15 are diagrams used to describe the manufacturing method ofthe semiconductor device 10B of the second embodiment. In FIGS. 13-15,components which are the same as those of FIGS. 4-11 used to describethe semiconductor device 10A according to the first embodiment and themethod of manufacturing the semiconductor device 10A are indicated bysame the reference number, and explanations are omitted.

The semiconductor device 10B according to the present embodiment ischaracterized in that a tape member 35 is provided on the lower surfaceof the semiconductor chip 11. This tape member 35 is for example appliedwith adhesive agent on both sides, and functions as an adhesive member.The tape member 35 has a predetermined thickness(indicated by an arrowh1 in FIG. 12) and also functions as a spacer. In addition, the area ofthis tape member 35 is smaller than the area of the semiconductor chip11. Therefore, there remains the area on the lower surface of thesemiconductor chip 11 where the tape member 35 is not provided.

Now, the manufacturing method of the semiconductor 10B of the abovestructure will be explained. FIGS. 13 and 14 show the mounting processof the manufacturing method according to the second embodiment. In thepresent embodiment, the element accommodation recess 21 is not formed ona holding board 19C, and as shown in FIG. 13, the tape member 35 isprovided at the position where the semiconductor chip 11 is mounted.Since the tape member 35 is a so-called double coated adhesive tape, asdescribed above, the tape member 35 can be easily provided to theholding board 19C.

Subsequently, the semiconductor chip 11 and the electrode member 13A aremounted on the holding board 19C. Here, the semiconductor chip 11 ismounted on the tape member 35. Thus by holding the semiconductor chip 11on the holding board 19C using the tape member 35 which functions as anadhesive member in the mounting process, the semiconductor chip 11 canbe securely held to the holding board 19C.

As shown above, by providing the tape member 35 in the mounting process,this tape member 35 functions as a spacer, so that the semiconductorchip 11 can be mounted on the holding board 19C with a distance of thethickness(h1) of the tape member 35 apart from the surface of theholding board 19C. Also, the area of the tape member 35 is smaller thanthe area of the semiconductor chip 11. Therefore, as shown in FIG. 14, aspace can be formed between the base of the semiconductor chip 11 andthe surface of the holding board 19C.

FIG. 15 shows the sealing process according to the present embodiment.By forming a space between the base of the semiconductor chip 11 and thesurface of the holding board 19C, the sealing resin 25 is also loaded inthis space when the resin package 12 is formed in the sealing process.Because of this, the base of the semiconductor chip 11 is such that itis covered with the tape member 35 and the resin package 12.

The semiconductor device 10B which is manufactured as above has astructure wherein the base of the semiconductor chip 11 is such that itis covered with the tape member 35 and the resin package 12, so thatwhen this semiconductor device 10B is mounted on the mounting board, thesemiconductor chip 11 and the mounting board are prevented from beingshort-circuited. Also because the resin package surrounds the lowersurface of the semiconductor chip 11, the semiconductor chip 11 isprevented from being separated from resin package 12. This may improvethe reliability of the semiconductor device.

In the following, a semiconductor device 10B of the third embodiment ofthe present invention and a method of manufacturing the semiconductordevice 10C is described.

FIG. 16 shows the semiconductor device 10C of the third embodiment.FIGS. 17 and 18 are diagrams used to describe the manufacturing methodof the semiconductor device 10C of the third embodiment. In FIGS. 16-18,components which are also the same as those of FIGS. 4-11 used todescribe the semiconductor device 10A according to the first embodimentand the method of manufacturing the semiconductor device 10A areindicated by the same reference number, and explanations are omitted.

The semiconductor device 10C according to the present embodiment ischaracterized in that electrode members 13B are extended outside theouter edge(indicated by an arrow A in FIG. 16) of the resin package 12.In an example shown in FIG. 16, the electrode members 13B are extendedoutside the outer edge of the resin package 12 by a width W.

By extending the electrode members 13B outside the outer edge A of theresin package 12, a test can be carried out by touching this extendedpart with a probe. Because of this, an operational test can be carriedout for the semiconductor device 10C after the semiconductor device 10Cis mounted on the mounting board.

Now, the manufacturing method of the semiconductor device 10C of theabove structure will be described. FIGS. 17 and 18 show the mountingprocess of the manufacturing method according to the second embodiment.The manufacturing method shown in FIG. 17 is characterized in that thesize of electrode accommodation recesses 20B formed on a holding board19D is larger than the size of the electrode accommodation recesses 20Aof each of the above described embodiments.

That is to say, the electrode accommodation recesses 20B are extendedmore than the electrode accommodation recesses 20A of each of the abovedescribed embodiments, so that they extend outside the outer edge A ofthe resin package 12. By using the holding board 19D, on which theelectrode accommodation recesses 20B of above structure are formed, thesemiconductor device 10C can be manufactured by using manufacturingprocesses similar to those of the above described embodiments.

Since the semiconductor device 10C is constructed such that theelectrode members 13B extend outside the outer edge A of the resinpackage, the semiconductor device 10C can be manufactured by usinglead-frame 36 which is shown in FIG. 18. This lead-frame 36 includes aframe body 37 which is larger than the outer edge (indicated in dash-dotline) of the resin package 12 and the electrode members 13B integratedin this frame body 37.

After connecting the semiconductor chips 11 to the lead-frame by thewires 18, the resin package is formed by performing the sealing process.When the sealing process is complete, the part within a dash-dot line Bis sealed in the resin package 12. Therefore, when the sealing processis complete, a part of the electrode members 13B and the frame body 37are placed outside the resin package 12.

Subsequently, the frame body 37 is removed by cutting the lead-frame 36along a dash-dot line C. Because of this, a part of the electrodemembers 13B extends outside the resin package 12, and the semiconductordevice 10C shown in FIG. 16 is manufactured. By manufacturing thesemiconductor device 10C using the lead-frame 36, existing semiconductormanufacturing equipment can be utilized while improving manufacturingefficiency.

In the following, a semiconductor device 10D of the fourth embodiment ofthe present invention and a method of manufacturing the semiconductordevice 10D is described.

FIG. 19 shows the semiconductor device 10D of the fourth embodiment.FIG. 20 is a diagram used to describe the manufacturing method of thesemiconductor device 10D of the fourth embodiment. In FIGS. 19 and 20,components which are the same as those of FIGS. 4-11 used to describethe semiconductor device 10A according to the first embodiment and themethod of manufacturing the semiconductor device 10A are indicated bythe same reference number, and explanations are omitted.

A semiconductor device 10D according to the present embodiment ischaracterized in that electrode members include high-back electrodemembers 13C(having height indicated as H1 in FIG. 19) and low-backelectrode members 13D(having a height indicated as H2 in FIG. 19) havinga height lower than the height of the high-back electrode members 13C.

As shown in FIG. 19, the low-back electrode members 13D are provided onthe inner periphery which is nearer to the semiconductor chip 11 and thehigh-back electrode members 13C are provided at the outer periphery soas to surround the low-back electrode members 13D. Thus, by constructingthe electrode members with the high-back electrode members 13C and thelow-back electrode members 13D, the pitch between respective electrodemembers 13C and 13D can be narrowed, so that the semiconductor device10D can be a multi-pin structure.

FIG. 20 show a connecting process of the manufacturing process of thesemiconductor device 10D of above structure. As shown in FIG. 20, thedepth of first electrode accommodation recesses 20C for the high-backelectrode members 13C and the depth of second electrode accommodationrecesses 20E for the low-back electrode members 13D which are formed ina holding board 19E are assumed to be equal. Therefore in the mountingprocess, when the high-back electrode members 13C are mounted on thefirst electrode accommodation recesses 20C and the low-back electrodemembers 13D are mounted on the second electrode accommodation recesses20E, the degree of protrusion of each of the electrode members 13C and13D above the holding board 19E will be such as shown in FIG. 20.

In the connecting process, wires 18 are connected with the high-backelectrode members 13C and the low-back electrode members 13D ofdifferent heights, so that a so-called multi-stage bonding can beperformed. By enabling multi-stage bonding, neighboring wires 18 areprevented from touching each other, thus a fine-pitch structure and amulti-pin structure is achieved.

Now, the variant of a electrode member will be described. FIGS. 21A-21Dshow various types of the variant of the electrode member.

FIG. 21A shows an electrode member 13E. The electrode member 13E ischaracterized in that a flange 38 is formed on its upper part and thatthe flange 38 forms a predetermined space(indicated by h2 in FIG. 21A)with the upper surface of a holding board 19F when an electrode member13E is mounted on an electrode accommodation recess 20E formed in theholding board 19F.

When the sealing process is performed to the electrode member 13E of theabove structure, the sealing resin 25 forming the resin package 12 isalso filled below the flange 38, resulting in increase of the joiningstrength between the electrode member 13E and the resin package 12.Therefore, according to the present embodiment, the electrode member 13Eis prevented from remaining in the holding board 19F during theseparating process.

Electrode members 13F-13H shown in FIGS. 21B-21D are electrode membershaving an improved adhesiveness with respective electrode accommodationrecesses 20F-20H. As described above, when the sealing resin 25 entersbetween the electrode members 13F-13H and the electrode accommodationrecesses 20F-20H, the sealing resin 25 acts as an adhesive agent,thereby preventing the electrode members 13F-13H from separating fromthe electrode accommodation recesses 20F-20H during the separatingprocess. However, by improving adhesiveness between the electrodemembers 13F-13H and the electrode accommodation recesses 20F-20H, entryof the sealing resin 25 is prevented and the separating process issmoothly carried out. Each of the electrode members 13F-13H will bedescribed in the following.

FIG. 21B shows an electrode member 13F. The electrode member 13F ischaracterized in that the size of its upper part(indicated by an arrowW1 in FIG. 21A) is larger than the size of its lower part(indicated byan arrow W2 in FIG. 21A) and that the size gradually decreases from itsupper part towards its lower part. The size of the upper part W1 islarger than the size of the electrode accommodation recess 20F(indicatedby an arrow W3 in FIG. 21A) formed in a holding board 19G, and the sizeof the lower part W2 is smaller than the size of the electrodeaccommodation recess 20F(W1<W3<W2).

Since the periphery of the electrode member 13F always touches theelectrode accommodation recess 20F by employing the above structure,adhesiveness between the electrode member 13F and the electrodeaccommodation recess 20F is improved.

FIG. 21C shows an electrode member 13G. The electrode member 13G ischaracterized in that it is spherical and that the shape of theelectrode accommodation recess 20G formed in a holding board 19H issubstantially spherical so as to match the shape of the electrode member13G. At an upper part of the electrode accommodation recess 20G, thereis formed a hole having a smallest possible dimension for permitting theinsertion of the electrode member 13G. Therefore the electrode member13G will be mounted on the electrode accommodation recess 20G bypressing it into the electrode accommodation recess 20G. Because ofthis, the adhesiveness between the electrode member 13G and theelectrode accommodation recess 20G is improved.

FIG. 21D shows an electrode member 13H. The electrode member 13H ischaracterized in that a flange 39 is formed at its upper part and thatthe flange 39 touches the upper surface of a holding board 19I when anelectrode member 13H is mounted on the electrode accommodation recess20H formed in the holding board 19I. By employing this structure, theflange 39 functions as a plug which blocks the electrode accommodationrecess 20H. Therefore, the adhesiveness between the electrode member 13Hand the electrode accommodation recess 20H is also improved by thisstructure.

Further, the present invention is not limited to these embodiments, butvariations and modifications may be made without departing from thescope of the present invention.

What is claimed is:
 1. A semiconductor device comprising:a semiconductorchip; a resin package for sealing said semiconductor chip; electrodemembers embedded in and held by said resin package and partly exposedfrom a mounting surface so as to form external connection terminals,each of said electrode members being made of a single-piece metal memberhaving a rectangular shape viewed in a direction parallel to a mountingboard; and connecting parts electrically connecting electrode pads onsaid semiconductor chip with said electrode members.
 2. Thesemiconductor device as claimed in claim 1, further comprising a spaceron a lower surface of said semiconductor chip, said spacer having anarea smaller than an area of said semiconductor device, and a sealingresin forming said resin package surrounds said spacer.
 3. Thesemiconductor device as claimed in claim 1, wherein said electrodemembers extend outside an outer edge of said resin package.
 4. Thesemiconductor device as claimed in claim 1, wherein said electrodemembers include high-back electrode members and low-back electrodemembers having a height lower than a height of said high-back electrodemembers.
 5. The semiconductor device as claimed in claim 1, furthercomprising plating layers which are at least partly formed on saidelectrode members.
 6. The semiconductor device as claimed in claim 1,wherein said electrode members are made of one of solder and gold.